MAPLEWOOD — Two decades on the job, you get to know some guys pretty good.

Especially when the workplace is a firehouse. All those 24-hour shifts, you live together. Eat at the same table. Sleep in close quarters. And when a call comes in, you go out as a team, knowing if it gets bad, your life might be in your buddy’s hands.

Joe Callaghan has been a Maplewood firefighter for 20 years, and worked side by side with Greg Snell, who had 18 on the job.

For a few of those years they worked the same shift, bunking up at Maplewood’s satellite Station No. 2 on the corner of Springfield and Boyden. Satellite as in "small."

"There were only three guys there," Callaghan said. "Let’s put it like this: You didn’t get much privacy."

But what you got was a chance to become friends. Real friends, not just work friends. The kind of friends who get invited to children’s christenings and backyard barbecues and hear stories about the highs and lows in an average life.

Snell and Callaghan were those kind of friends. And more. The kind of friends where when one guy needed a kidney, the other guy gave it.

Greg Snell was a defensive end at Columbia High School, who went on to play linebacker at Morehouse College. His firefighting weight was about 260.

"He was a big, healthy dude," said Callaghan, a department captain. "Then he got sick."

It was eight years ago that Snell’s kidneys just went. One day at the firehouse, he felt like he was having a heart attack. The fire department EMTs took him to the hospital, where doctors told him his kidneys shut down. Just like that.

"It came out of nowhere," Snell said.

He started dialysis, three times a week, 4½ hours each time. It was a grind.

Eight months later, in November 2004, he was forced to retire from the job he loved.

"It was tough watching him deteriorate like that," Callaghan said. "Like I said, he was a strong guy. He was a bull. When we were on a call, he was a guy you knew you could count on. He was always a guy who was always in the thick of things. Most guys take pride in that. I’m like that, and most of the guys in department are like that, too, so we had a lot of respect for each other."

When Snell first got sick, he was not eligible for a transplant because he had a treatable cancer. It took awhile, but that cleared up, and about three years ago the Maplewood F.D. wanted to help find a donor.

"I know it sounds corny, but he was a beloved member of the department," Callaghan said.

So they brought him lunches and dinners when he was too sick to come by the firehouse and eat, like old times. They organized fundraisers for him.

"I can't say enough about those guys," Snell said. "The fire department and my church (First Baptist of Vauxhall) got me through this."

With prayers, and money, and Joe Callaghan’s kidney.

"When we found out he was on the donor list, we had a meeting about what we could do for Greg," Callaghan said. "Some guys were thinking we could take out billboards, asking for donors. I thought, ‘Why should we do that?’ "

Callaghan offered Snell his kidney.

Snell said no.

"He has four kids," Snell said. "I couldn’t do that. Kidney disease can come on anybody quick. I didn’t want Joe to take a chance like that."

But two more years of dialysis wore him down. When Callaghan offered again last year, Snell accepted. Reluctantly. But he accepted.

So Callaghan talked it over with his kids, and his wife, Mary, who is a nurse.

"They were cool with it," Callaghan said.

Cool with it. That statement pretty much says it all about Callaghan. As if giving a kidney was say, like, going on a weekend fishing trip with his buddies. "Yeah, my wife is cool with it."

Snell also talked to Mary Callaghan.

"I wanted to make sure it was okay with her," Snell said.

So they went for testing, and the truth is, they weren’t a good match: only about 60 percent, in blood, tissue and antigens. Just a few years ago, Callaghan would have not qualified as a donor. But advances in medications that stop the body’s immune system from rejecting transplanted organs put the Callaghan-Snell match in the acceptable range.

On Nov. 1 the men were brought to separate operating rooms at St. Barnabas, and Joe Callaghan’s 48-year-old kidney was put into Greg Snell’s 47-year-old body.

"I knew the risks. I know them now," Callaghan said. "But I’m not a squeamish guy. I rode the ambulance for nine years. So I didn’t get all freaked out about it."

All went well, and both men are recovering just fine. Snell is returning to a normal lifestyle, not having to limit his fluid intake to 32 ounces a day or be so severe in his diet. And in January, Joe Callaghan will return work.